One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,4)(5,6)(7,8)(9,10,14,15)(11,19,20,16)(12,17,21,23)(13,18,22,24)(25,26,30,33)(27,31,36,32)(28,29,38,40)(34,35,37,39)(2,6)(4,7)(10,15)(13,22)(16,19)(17,23)(25,27)(26,31)(28,37)(29,39)(30,36)(32,33)(34,38)(35,40) involution — undirected(2,6)(3,8)(11,20)(12,21)(16,19)(17,23)(25,27,30,36)(26,32,33,31)(28,37,38,34)(29,35,40,39)(1,3,5,8)(2,7,6,4)(9,11)(10,16)(12,18)(13,17)(14,20)(15,19)(21,24)(22,23)(25,27)(26,31)(28,34)(29,35)(30,36)(32,33)(37,38)(39,40)(1,2)(3,7)(4,8)(5,6)(9,12)(10,17)(11,18)(13,16)(14,21)(15,23)(19,22)(20,24)(25,28)(26,29)(27,34)(30,38)(31,35)(32,39)(33,40)(36,37) involution — undirected(1,4,5,7)(2,8,6,3)(9,13)(10,18)(11,17)(12,16)(14,22)(15,24)(19,21)(20,23)(25,29)(26,28)(27,35)(30,40)(31,34)(32,37)(33,38)(36,39)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.